Abstract: Mo2FeB2 boride base cermets produced by a novel sintering technique, called reaction
boronizing sintering through a liquid phase, have excellent mechanical properties and wear and
corrosion-resistances. Hence, the cermets are applied to the injection molding die-casting machine
parts and so on.
Metal injection molding (MIM) is a suitable processing route for the mass production of
complex shaped and high performance components. In general, it is difficult for the liquid phase
sintered materials to be applied to the injection molding process because significant shrinkage and
deformation occur during sintering.
In this study, the MIM process was applied in the production of Mo2FeB2 boride base cermets
parts. We investigated that the effect of deoxidization and sintering temperature on mechanical
properties and deformation of the cermets. As a result, deoxidization temperature of 1323K and
sintering temperature of 1518K were suitable. The MIM products of the cermets showed allowable
dimensional accuracy and the same mechanical properties as the press-sintered.

Abstract: Pure Ti, TiN and graphite powders were mechanically alloyed to synthesize Ti(C,N) powder
with nanocrystalline microstructure. The effect of milling variables on the synthesizing behavior of the
powders was investigated. As a result of milling, nano Ti(C,N) phase was synthesized by mechanical
alloying. After that, Ti(C,N)-based cermets were fabricated with the powders as raw ceramic materials. It
was found that the grain size was affected by the content of mechanical alloyed (MAed) Ti(C,N). The
grains of the cermet with suitable MAed Ti(C,N) powder were smaller than that of the typical cermets
prepared from the commercial powders, and the rim phase surrounding the hard core was also complete.
As a result of this, the transverse rupture strength and hardness of the cermets were improved.

Abstract: In this research, titanium carbide-nickel (TiC-Ni) composites, with tungsten carbide addition, were fabricated by using a powder metallurgy technique. The TiC-Ni mixtures containing between 0-15 wt. % tungsten carbide (WC), were compacted and then sintered at 1300°C and 1400°C, respectively. The phase formation and microstructure of the WC-added TiC-Ni composites have been investigated by X-ray diffraction and scanning electron microscopy techniques. Mechanical properties of these composites were assessed by an indentation technique. The X-ray diffraction patterns showed no evidence of tungsten rich phases in the sintered WC-added cermets. This indicates that during the sintering process, tungsten carbide particles were dissolved in metallic binder phase (Ni phase) via dissolution/re-precipitation process during liquid phase sintering. The liquid phase formed during sintering process could improve sinterability of TiC-based cermets i.e., it could lower sintering temperatures. The TiC-Ni composites typically exhibited a core-rim structure. The cores consisted of undissolved TiC particles enveloped by rims of (Ti, W)C solid solution phase. Hardness of TiC-Ni composites increased with WC content. Sintering temperature also had a slight effect on hardness values.

Abstract: TiCN-based cermets with different amounts of SiC nano-whiskers were prepared by spark plasma sintering. The microstructure and mechanical properties of the as-prepared cermets were investigated. X-ray diffraction revealed that there were no SiC peaks detected, turning out some peaks of new carbide and silicate hard phases. Scanning electron microscopy indicated that there were more and more pores in the cermets with increasing amount of SiC whisker added, and the fracture mechanism of the cermets was mainly inter-granular fracture. With increasing addition amount of nano-SiC whisker, the hardness and flexural strength of the cermets increased first and decreased then, presenting the highest hardness (2170 HV) and flexural strength (750 MPa), respectively, when the addition content of nano-whiskers is 2.5 wt%.